New LG passive TV has best 3D - Opinion - Page 8

It doesn't matter how many arguments are made that the LG Passive technology gives full 1080p 3D. The fact of the matter is that I see the black horizontal lines when I view it, unless I stand really far back away from it, far enough back that the 3D becomes sometimes too great. (Per the user manual, LG lets you adjust the 3D depth and viewpoint, which may help with this: • 3D Depth : Adjust 3D depth between the foreground object(s) and the background. • 3D Viewpoint : 3D image can be made closer or farther from user.)

I don't see those lines on the active-shutter 3D TVs. That said, I prefer the 3D image on the LG to the active-shutter TVs - it's not just brighter (because the glasses aren't as dark, nor do they electronically darken), but also looks better, at least for the demo scenes, and possibly the lack of flicker helps. Having lived with a 50" LCD RPTV for 8 years, we would want the 65" LG, but that means the lines would be even more pronounced at our regular sitting distance than on the 55" TV when viewing 3D.

But it appears that neither LG nor anyone else with passive 3D is going to double the horizontal lines anytime soon on 3D HD TVs, except for the soon-coming-but-probably-way-too-expensive 4K TVs (Sony's is $25K list price! http://store.sony.com/c/S_4KTV/en/c/S_4KTV - total stupid purchase IMO; wait for 8K if you're going to pay that much) - plus, 84" would probably be too large for what we want, so the only passive one I see 60" or larger that might sell for under $3K is LG's (I don't want the cinema-wide TVs). We may have to settle for the 65" LG and just live with lines when watching 3D.

Or get the 70" Aquos active-shutter.
Edited by eweiss - 9/28/12 at 12:48pm

Vizio has a 65" model as well.

You're right. I wonder if it has better (i.e., less visible) horizontal lines? No reviews yet.
Edited by eweiss - 10/2/12 at 8:38pm

I've been wanting to say the same thing, but didn't have the patience to type out an explanation. What you are saying is 100% the reason people WILL be losing some image resolution with passive. GOOD JOB on making a well explained point!

The new 65" vizio is out now , the model is 651 instead of 650. Only difference ive seen listed is the new one is 240hz instead of 120hz.

Please, Please, there is no screen flicker on current 240 hz. active displays. I entertained eight friends a week ago and asked about flicker, headaches Etc. They had none of these problems during two hours of viewing. The glasses open and close @ 60 hz. A movie on any display is 24 hz. There isn't noticeable flicker viewing that.

I think when some people complain about "flicker," they're actually seeing tearing. The principle behind active shutter technology is that despite small a time difference between the left and right images, they're displayed fast enough that our brains determine them to be simultaneous. This works most of the time, except when cycling to a new frame. One eye sees the previous frame for the last time, while your other eye sees the next frame for the first time, and your brain attempts to put these two frames together. If there's a fair amount of movement (difference) between the two frames, your brain can't put them together, and you see a brief moment of tearing. This is where higher frame rates (more frames but less difference between them, meaning less noticeable tearing) and passive technology (zero tearing) have the advantage.

Thanks Airion. Good explanation and I believe what you say. I'll drop my issues on the flicker question.

Yes, I stand corrected, and edited my post accordingly. I'm waiting for the reviews. It might be at our Costco by now. The price is tempting.

http://store.vizio.com/led-lcd-hdtvs/m3d651sv.html
Edited by eweiss - 10/7/12 at 6:19pm

As soon as I think I have decided which way to go (active vs passive) I see a debate like this one and my heart sinks yet again

Right, I want to use my new screen as my main PC monitor for watching tv shows/films/playing games etc. in 2d and 3d.

From what I can gather, active shutter glasses only allow 24/30fps per eye@1080p due to HDMI bandwidth limitations or 60fps per eye@720p, whereas passive will allow an interlaced 1080 signal displaying@60fps using either the Zalman hack for the nvidia 3dDrivers or iz3d?
If I have understood this correctly then for pc gaming on a 3dTV , passive is the only way to go, as 30fps is just not acceptable for gaming.

If this is the case, I would take the slight loss is resolution rather than halving my framerate.

Have I understood this correctly?

Got the panasonic 55ET5b and sit around 6-7 feet from it and cannot see the black lines.
The only thing I notice is some slight aliasing depending on what content I am viewing. On sharp lines etc. it is visible, but only slightly and doesn't bother me at all.

The LG's have some nice 3D.

I am guessing regular 2D picture quality is not a priority here?

I own an LM7600 and the 2D picture quality looks great to me. The TV has a ton of image and color tweaking options, its just a matter of working with them until you get an image that is pleasing to you.

But also notice that these unshared ares of vision are, by their nature--as with things viewed with the naked eye in the real world--less distinct and harder to perceive because of the perceptual overlap, with the left eye's information juxtaposed with the right's. It makes any actual drop-off in resolution with the passive system much more difficult to perceive. And in my own subjective assessment in switching back and forth between active and passive technologies....even when focusing on these L/R "mash-up zones," I cannot say that active has the edge in the way it plays to the eye and is processed by the brain. I guess if passive has to employ a little sleight of hand with resolution, these are the least discernible areas of the 3D image to do it in.
Edited by JackN - 5/7/13 at 12:19pm

I'm not so sure about that. Place one finger between you and your PC screen. Part of the screen's image is blocked in each eye, but if you ignore your finger and concentrate on the screen, you can see the screen in full just fine, even where your finger is "overlapping." There's certainly no resolution loss in the real world.

I don't want to discount subjective impressions, but this is subjective. The resolution loss is real, but whether it matters or not depends on your viewing conditions. If you were to sit close enough, you would definitely see black horizontal lines, a loss of detail, in those zones on passive (and elsewhere). If you didn't see them, you simply weren't sitting close enough, and at that distance there really is no advantage to active's resolution. It's just important to recognize this as subjective and not the case for everyone.

It's like 720p vs 1080p vs 4k. You don't have to sit too far back for them to all look the same. This matters, but it doesn't mean there's no merit to higher resolutions.

I agree that there's no loss of resolution in the real world. My point was that the area of visual overlap helps to mask the loss of resolution in the passive 3D system; on Passive 3D TV as in life, it is a murky area of human perception. In your example of holding a finger before the PC monitor, notice how--in focusing on the monitor beyond the finger, with the finger centered directly in our line of sight--our juxtaposed L/R eye view of the monitor presents us with a less distinct image because the right eye's unobstructed view of the monitor is "contaminated" by the left eye's perception of the finger and vice versa. The "mash-up" zone where we are simultaneously seeing unobstructed and obstructed viewpoints combined may not be composed of lesser resolution from eye to eye, but it renders the conflicting imagery less vivid, distinct and discernible. It is in this jumble that the acknowledged drop in passive 3D's "unshared" visual real estate becomes less obvious and--depending on the viewer--perceptually moot, since the human brain has trouble organizing this "binocular overlap" information anyway. Simply put, the loss of resolution in the Passive 3D process in areas of stereo image overlap is hard to see, process...and probably won't be noticed by many. But that's where things get subjective again.
Edited by JackN - 5/7/13 at 9:51pm

Do you have any scientific references to back this up? I just don't see this effect in practice.

With due respect I think you might be clouded by owner's bias, with an incentive to come up with reasons why your TV doesn't have any practical disadvantage. Does this same reasoning convince you that a 4k passive panel's full 1080p per eye 3D is perceptually moot?

Empirical study as reference? Tools: Index Finger, PC Monitor, Binocular Vision. But point taken; I shouldn't be making blanket statements about "the brain," even if further--large scale--study might bear them out. I can speak with authority about my own, subjective perception, which is where this issue is decided for many of us. A practical disadvantage for LG's passive tech would have to be perceptible...to me.

Technical specifications might offer some guidance into what key, areas of performance to look for in comparing passive and active 3D panels. In the end, however, the only rational choice is qualitative, not quantitative. Go with what you like better as it comes in at the eye, not how it stacks up on a specs sheet.

I would love to see a 4K passive panel in action; it's a good bet it would offer visible improvements, even in those hard to suss out areas of binocular overlap.

But the play's the thing, and--as my index finger has shown me--things could still be a little dodgy in "the overlap zone."

Owners bias? Not so much in my case, but I can't rule out the possibility of "regular access bias." The Active 3D model I've logged fewer hours on is in the custody of friends...
Edited by JackN - 5/8/13 at 6:45pm

Last night I cued up a few more native 3D titles on the LG and looked for specific instances along edge-lines of objects where, for example, the right eye would be seeing them, the left eye beyond...in an effort to find a practical disadvantage of the passive process. I sought out objects closer to the viewer's point of view so that there would be the greatest L/R eye discrepancy in terms of which areas of the visual field were "shared" by each eye. With glasses off, I could clearly see the phenomenon we've been discussing; halved resolution where the passive system could only employ half of its available lines to render the background, half for the object. There was an apparent thinness to each element, and black lines galore. If I had to wager before putting the glasses back on, I would have bet it would point out where the passive process would fail to provide a convincing illusion of 3D. But, polarized lenses in place, it gels into a visually coherent illusion. It doesn't seem like it ought to--based on what the LG is integrating into its "fused" 3D image--but there wasn't any discernible downside to the process as far as I could see it. Just as I found with "the finger test," the binocular overlap looks very much like that when solid objects--and the space beyond them--are viewed directly in the world. I do agree that if specifications alone decided these things, the active process would come out on top. But in the realm of perceptual sleight of hand, the LG really does an uncanny job of "suggesting" full resolution in those stereo image collision zones. The lack of full 1080 per eye here doesn't seem to matter a jot... If you can't perceive its absence, should it? I'm going to take the same 3D titles over to the Active Plasma, see how the scenes in question perform; I'll come back and report on whether active has an edge...in edge-lines.
Edited by JackN - 5/9/13 at 4:05pm

The issue isn't that the halved resolution prevents the image from become a cohesive 3D whole. The fact is it is half resolution and it's physically impossible to be full resolution in each eye, especially in these half-occlusion zones. That doesn't mean the image can't look good. If you're not sitting close to the display, it's not possible to see it.

That's the critical factor you've left out in your evaluation, your screen size and viewing distance.
Edited by Airion - 5/9/13 at 5:05pm

How about a stereo analogy? In order to raise the volume by 3dB, one has to double the power of the stereo. The human ear perceives only a small change in volume at double the power.

For a difference in resolution, a similar thing is true for vision. When HD came out, some people didn't think the difference was worth it, and that was the difference between 480i and 1080P, and there would be even less of a perceptible difference with 540 vs 1080. Distance from the screen also makes a big difference, just as distance from a speaker does. At a moderate distance, 720 and 1080 can be indistiguishable from each other.

Just as an audiophile recognizes the need for more power, a videophile wants more resolution and that is why 1080 and 4K is the future.

Passive TVs use a workable tech to get the cost of glasses advantage, and most people want cheap and convenient over expensive, no matter the quality. Low rez MP3s and movies on one's phone are perfect examples of that market.

So we can stop debating, there's room for everyone and one is not better than the other, because better is measured differently by different people.
Edited by Augerhandle - 5/9/13 at 5:44pm

I'm about 9 feet away from a 55 inch panel.

Any indication whether a greater number of lower resolution frames--as with passive over active--could be interpreted as a more detailed image? In other words, when does more sequentially delivered information per second best the detail--in a perceptual sense--of higher resolution, yet fewer frames?

...Trying to account for ways the specs could be skewed by the synapses.

According to this chart, you would be only able to resolve a little more than 720p. Certainly not full 1080p, so you shouldn't be able to see the resolution loss.



It certainly matters for motion resolution. There's no difference between passive and active in terms of frames per second, but I think I know what you're getting at. Because of how active works, there's motion tearing. When a frame changes, there will be a moment when your right eye sees a new frame while your left eye is seeing (with persistence of vision) the previous frame, and your brain has to try to put them together. If there's motion, a difference between the two frames, your brain can't do it and it looks weird for an instant. I feel this is one of the bigger problems with active, and a clear advantage of passive. It's a different issue from static 1080p resolution though.

If you are looking for areas where passive 3D flaws show strong, look at the rim of a coffee cup in 3D.

I find that this regular, harsh edge is an excellent example in many cases of the damage the FPR does to image quality, especially if the camera pans vertically at all you end up with crawling lines around the edge of the cup.

I can look for specific examples but I think I was noticing this in Jurassic Park recently... I would think any white/light mug on a dark background would exhibit this, especially if it's reasonably small on screen.


As for the comparison on resolution it's tempting to say 540p is so low res it's almost 480p!

Except you forget it's 1920x540 per eye... that is a LOT of horizontal resolution.

720p is less than 1 mill pixels

1920x540 is just over 1 mill pixels.

So actually each eye is seeing more pixels than 720p...

The term "Half 1080p" is kind of like saying a 42 inch tv is half as big as an 84 inch tv. Sure it's half the size in one direction but it's not half the total number of square inches... so passives 540p is half 1080p VERTICALLY but not horizontally...

And this is all rendered moot by the point I have made before that no current resolution scheme describes an image flaw that inserts pixel helght black bars horizontally into an image.

Resolutions are given with the expectation that every pixel is evenly seperated from others and with as little distance as reasonably possible.

So we aren't talking 540p at all, we are talking 1080p with massive image occlusion.
Edited by Devedander - 5/12/13 at 11:23pm

I appreciate all the feedback; it's helping me understand these technologies a lot better.

Anyone tried scaling up a 2.35:1 3D Blu-ray to the full height of the screen on a passive set? Since the wider screen format does not utilize as much of the display area of the panel, I wondered whether zooming the image could get me a little closer to the way a 1080p 3D Blu-ray might perform on a 4K set. I guess the zoom has to be actual in order to make use of more of the available resolution from the Blu, not just a re-sampling of the frame as it appears on the screen. I don't know enough about the way "cinema zoom" functions (on an LG 55LM7600, not done via the Blu-ray player), but the results were impressive; significantly more detail seemed to be revealed. That could mean less resolution was tossed out and more detail registered for each eye, along with--for people that notice it--improved performance in the unshared areas of visual overlap. How close this could get to 4k performance--where the full, Blu-ray resolution for each eye could render--I'll leave to others to do the math on. There's a significant amount of side cropping involved, granted; the point is just to see how the passive process might perform with more available resolution in play; a tease of 4k, passive 3D today...

I guess it's all in the zoom... I'll see what I can find out about that...

The zoom options are not available in 3D mode on my LM4700... would be nice, even though I tend to faovr the full filmed frame over a crop, the use of additional screen space and removale of the black bars would be very welcome.

It's a nice feature, and a surprise, since most Blu-ray players don't even seem to offer it. I don't use it much, as foregrounding/frame composition is so important to the 3D effect. But it's great for this kind of testing, or adding a notch or two of zoom when you crave a greater sense of immersion from something in the 2.35:1 ratio.

Still no answer on whether the LG is unpacking more resolution from the Blu-ray, or re-sampling, but it certainly looks like the former. Can't see why they couldn't work out the circuity to make use of more of the full L/R eye resolution as delivered via HDMI and just render more of it depending on user defined zoom factor. I'll keep looking for info.